SLVAFJ8 may   2023 TPS7H5001-SP

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2System Design Theory
    1. 2.1  Switching Frequency
    2. 2.2  Leading Edge Blanking
    3. 2.3  Dead Time
    4. 2.4  Enable and UVLO
    5. 2.5  Output Voltage Programing
    6. 2.6  Soft Start
    7. 2.7  Sensing Circuit
    8. 2.8  FAULT Mode
    9. 2.9  HICCUP Mode
    10. 2.10 Slope Compensation
    11. 2.11 Output Capacitance
    12. 2.12 Compensation
  6. 3Test Results
  7. 4Bill of Materials
  8. 5Schematics
  9. 6PCB Layouts
  10. 7References

2.12 Compensation

Before the compensator component values can be found, the power stage transconductance was calculated as shown in Equation 13.

Equation 13. gmps= RCS x CCS x fSWLOUT=1 kΩ x 100 nF 560 nH=179

The following equations were used to achieve the desired crossover frequency, and values used as a starting value. These values were optimized during lab testing and movement of the poles and zeros further out in frequency were determined to work better for the converter as a whole. Note that the resistor used in calculations is the value that was settled on in lab and not the answer provided by the equation.

Equation 14. R C O M P =   2 π   x   f c   x   V O U T   x   C O U T   g m e a   x   V R E F   x   g m p s = 2 π   x   15   k H z   x   0.8   V   x   20   m F     1800   μ S     x   0.613   V   x   179   S = 7.6   k Ω
Equation 15. C C O M P =   V O U T   x   C O U T   I O U T     x   R C O M P = 0.8   V   x   20   m F 80   x   6.98   k Ω = 28   n F  
Equation 16. f e s r =   1   2 π   x   C O U T   x   E S R   =   1 2 π   x   20   m F   x     0.1   m Ω =   79.6   k H z  
Equation 17. C H F =   1   2 π   x   R c o m p   x   f e s r   =   1 2 π   x     6.98   k Ω   x   79.6   k H z =   285   p F